ENNOLA, Veikko. On a Theorem of erdös and Turan. Mathematica Scandinavica, Berkeley, CA, United States, v. 22, p. 75–80, 1968. DOI: 10.7146/math.scand.a-10872. Disponível em: https://journals.msp.org/mscand/article/view/2431. Acesso em: 25 jul. 2026.